The Royal Canadian Navy's only submarine on the East Coast will be pulled from service for up to a year because of engine woes, CBC News has learned.

HMCS Windsor, which completed a $209-million refit just 18 months ago, will be hauled from the water in March, the navy has confirmed to CBC News.

A navy spokesperson said one of HMCS Windsor's two diesel engines will be removed and replaced during the unscheduled docking.

4 submarines, 1 ship-shape:

Even after HMCS Windsor's $209-million refit, the submarine is still not capable of firing torpedoes. Only one of Canada's four submarines has ever fired a torpedo, even though the navy acquired the submarines in 1998.

The West Coast-based HMCS Victoria — which was discovered to have a large dent in its hull after delivery — is the only submarine capable of firing torpedoes, and has unrestricted diving and movement.

The navy recently announced HMCS Chicoutimi was back in the water for sea trials after that submarine spent nearly 10 years on dry land because of a fire that killed a sailor.

HMCS Corner Brook was sidelined after a devastating collision with the sea floor in 2011 that tore off two of the sub's torpedo doors and left the bow badly shattered. The Corner Brook is not slated to be back in the water again until at least 2016.​

A naval source told CBC News the job will take at least seven months but could last longer, depending on how the massive 16-cylinder diesel engine is stripped from the submarine.

Lt.-Cmdr. Alain Blondin responded to CBC's inquiries late Wednesday. He said the work is scheduled to take place between late March and September.

Blondin said the replacement generator is "projected to cost $1.5 million, including labour, already procured materials and external services. While the defective generator is being replaced, other maintenance and engineering changes will also be carried out," he said.

"However, this cost will not be known until the repair agent can survey the defective unit."

Blondin said the cost for the engine itself is $1.35 million, which he said is already a part of the "national spare parts inventory for the submarine fleet."

The broken Paxman Valenta engine weighs eight tonnes and was commonly used to drive British trains.

Canada's used British-built submarines are fitted with a special hatch that may allow the navy to simply pull the engine from the 20-year-old HMCS Windsor. But if the hatch — called a Dutch breach — turns out to be too small, the navy will be forced to cut the submarine in half to remove the engine.

It is likely the 2,400-tonne Windsor will be hauled from the water at the navy's dockyard in Halifax and stored in a newly constructed $20-million submarine shed that will shelter the sub from the elements.

HMCS Windsor should have been operational until 2018 after a five-year refit which began in 2007. The refit was to take two years and cost $45 million. But in April, Capt. Luc Cassivi, director of Canada's submarine force, told CBC News the final tally was $209 million.

Shortly after the navy slipped the Windsor back into Halifax harbour in the spring of 2012, the diesel engine was declared unusable. The diesel engine is used to charge the batteries the submarine depends on to drive electric propulsion motors when submerged.

The engine failure meant that even after hundreds of millions spent on upgrades, the Windsor only had one working engine, which restricted the sub's ability to dive and manoeuvre.

The submarine's 48 crew members were forbidden to take the submarine from home waters because of the useless engine.